VCR recording narration

Hello,

I just recorded my first tape on a JVC VCR (HR-S3911U). When I played back the tape, there was a narration that sounds like it must be for the sight impared. It was describing the action in the movie. This was a Mystery! program on PBS.

I never even knew this existed, as I never heard anything like this while watching TV. What am I doing wrong? I just had cabel TV installed and this is my first time taping a TV program.